Automatic latch



y 94 L. F. 'HARZA AUTOMATIC LATCH Filed Dec. 50, 1939 555; n W. Wm, &\\.|ll|. 2 my; o.o km %\MW%N J INVENTOR'.

ATTORNEY below water level.

Patented July 20, 1943 UNITED STATES PATENT OFFICE AUTOMATIC LATCH Leroy F. Harza, Highland Park, Ill. Application December 30, 1939, Serial No. 311,716

8 Claims.

nection' with a lifting beam for an hydraulic gate.

An important object of the invention is in 'the provision of a simple and efficient latching device which may be manually changed for automatic operation, depending upon the movement of the lifting beam.

A further object of the invention is in the provision of an automatic latch of this kind which is simple in construction, not likely to get out of order, and effective and efficient in operation .even though positioned below wate level.

A still further object of the invention is in the provision of a weighted latch which may beeasily operated by hand to effect a latching or unlatching movement.

Other and further objects of the invention will appear hereinafter, the accompanying drawing illustrating a preferred embodiment of the invention, in which Fig. 1 is a side elevation of. a latch constructed in accordance with the invention;

Fig. 2. is a top view of the structure shown in Fig. 1; and

Fig. 3 is a sectional view of the latch as taken on the line 3-3 of Fig. l.

In automatically connecting or disconnecting two movable members as for example in raising or lowering a heavy load by means of a crane or a lifting beam, it is frequently desirable to engage or disconnect the load without manual attention to the latch at the time of the actual connection or disconnection thereof. This may happen for example when a heavy hydraulic gate is to be raised or lowered in guideways by means of a crane or lifting beam from a position The present invention overcomes this difficulty by providing a movable latch which is loaded by means of a weight and tends to swing either into a hook-engaging posibeams I having arounded upper extremityt aton side of the hook and an inclined surface l extending toward the other side thereof, with a rounded extremity H at this side for partially enclosing an inverted hook seat l2.

A lifting beam comprises side channel plates i3 connected and spaced apart at intervals by cross plates I4 and a supporting stirrup l5 at the end (each end) of the beam which is preferably co-extensive in length with the gate itself so that the stirrups will restand engage upon the end beams 6 thereof and is adapted to be loosely inserted in the end guideways 5.

This lifting beam is supported and upheld in any suitable manner as for example by means of a hook l6 of an overhead traveling crane (not shown), but preferably having two lifting hooks l6 symmetrically spaced above the center line of the lifting hooks 8 at each side of the gate, although a smaller. gate would have only one hook located in the center of the gate. The lifting beam sliding downward in the structural grooves 5 tends to space the latching devices in correct relation to the hooks which they are to engage attached to the gates as shown.

Each of the crane hooks engages a crosspin ll connected between the upstanding projections of side plates 18 rigidly secured to the spaced side plates I3 of the lifting beam.

A pivoted latch member comprising a pair of plates 20 have a connecting pin 2| at their outer end adapted to be seated in the hook seat or bight l2 and the inner ends of these plates are mounted upon bearing members 22 which ;in turn are mounted upon a bearing pin 23 having a head 24 at one end and adapted to be inserted through openings in the lifting beam plates l3 and also through the supporting plates.l8 and projecting from the opposite side of the lifting beam. At this end the pivot pin is formed with a notch 25 engaged by a keeper 26 which is bolted or otherwise secured in place to prevent disengagement of the bearing pin from the lifting beam. At the upper or pivoted ends ofthe latch plates 20 are shoulders 21 and 28 at opposite sides of the bearing pivot 23 which is substantially in line with the bight or opening of the hook 8. The shoulder 21 at one side is higher thanthe shoulder 28 at the other side and both shoulders are adapted to be engaged by a crosspiece 29 carried by an arm 30 having a bearing 3| at one end surrounding the pivot pin 23 between the bearings 22 of the side plates 20 and having a weight 32' at its outer end adapted to hold the arm with the cross-piece 29 in engagement Witheither shoulder 21 or 28,. depending upon which side of the pivot this weighted arm is rotated. A handle 33 for manual engagement is preferably disposed outside of the weight so that by grasping it the arm can be swung about the pivot 23 to engage either of the shoulders 21 or 28, depending upon the action desired.

The shoulders 21 are located at the side of the latch opposite the hook opening I2 so that when the weighted arm rests upon them it tends to swing the latch out of engagement with the hook 8 and when the Weighted armengages the shoulders 28 it tends to swing the pin 2| of the latch member into engagement with the bight of the hook member 8. When the weighted arm engages the shoulders 28 of the latch plates 20, the downward movement of the lifting beam with respect to the hook 8 will cause the pin 2| of the latch to engage upon the inclined surface lb of the hook, the continued lowering movement moving the pin 2| below the rounded extremity H and swinging the pin into the rounded seat or bight of the hook.

In operation, when the gate is in its upward position supported by any suitable means in the guideways, with the lifting crane and lifting beam in use elsewhere, and it is desired to lower the gate, the crane would be moved along to pick up the lifting beam, lowering it into the guide grooves 5. The weighted arm might then be in a position at the left of the pivot 23 which would.

tend to hold the latch open. As soon as the beam is lowered opposite the hook the weighted arm is thrown over to the other position at the right side of the pivot, causing the latch to engage the hook. Even if the weight were in this latter position when the beam is lowered the sloping upper surface ll] of the hook will push the latch over and the weight would cause it to-engage in the hook. The lowering movement of the lifting beam with respect to the gate is limited by the stirrups l5 so that as soon as the latch pin is thrown over against thehook the lifting beam is lifted slightly, engaging the latch pin 2| and slightly lifting the gate. Before lowering the gate the weighted arm is then moved from the position at the right of the pivot 23 to a position at the other side thereof which-tends to open the latch but cannot do so because of the weight of the gate on the hook and latch at that time. Whent the gate is lowered to its bottom rest position, the lifting beam continues its downward movement until the stirrups l5 engage the end beams 6, or until the weighted arm throws the latch out of engagement with the hook whereupon the beam may be lifted by the crane free from engagement of the hook and latch mechanism.

On the other hand, when the gate is in its lowered position the top of the gate and even the lifting hook 8 may be submerged far .below the surface of the water. In this case the operation of the latch mechanism is just reversed, the lifting beam when lowered carrying the latch Weighted to engage the hook, the beam being lowered so that the pin 2| engages the inclined surface l0 before engaging in the bight of the hook.

With this'construction it is possible to set the hook and latch mechanism for automatic engagement or disengagement both below and above the surface of the water,'depending upon the action desired. It is obvious that the same mechanism may be applied to both ends of a lifting beam with the hooks and latches properly spaced apart to operate simultaneously. It'is also obvious that the hook and latch mechanism might be reversed, that is, the hook might be carried upon the lifting beam and the latch located and projecting outwardly from the upper edge of the gate.

While this latch mechanism is particularly adapted for handling hydraulic gates by means of lifting beams it may also be used for any other loads for other purposes if desired.

I claim:

1. A hook and latch mechanism comprising interengaging members in which one of the members has a weight engaging it and relatively movable to one side or the other of a central upright position and tending in one position to hold the members together and in the other to move them apart depending upon which side of the central position it is placed.

2. An automatic hook and latch mechanism comprising inter-engaging members movable together slightly beyond their inter-engaging position, one member being pivoted to swing relatively into and out of position to engage the other, and a weight relatively movable to engage the pivoted member at one side or the other from an upright central position and tending to press the pivoted member into or out of position engaging the other member when the members are moved together slightly beyond their inter-engaging position.

3. In a latching mechanism, a hook, a latch therefor comprising a plate with "a pin at one end and mounted upon a bearing pivot at the other end, the plate having shoulders at opposite sides of the pivot, a weighted arm also mounted on the pivot and relatively movable to engage the shoulders at one side or the other of the latch for tending to press the pin into engagement with the hook or outwardly therefrom, depending upon which shoulder is engaged.

4. In a gate lifting latch, a gate member mounted for movement in a guide, a lifting beam mounted for raising-and lowering movement and limited by the guide of the gate, a hook attached to the gate having a reverse engaging notch, a latch pivoted 0n the beam with a pin at the outer end adapted to engage in the notch, a weight also pivoted in the beam and adapted to engage the latch at opposite sides of the pivot formoving it into or out of position to engage in the notch, means for raising and lowering the beam and moving the latch into or out of engaging position with respect to the hook depending upon the position of the weight, and a stirrup carried by the beam for limiting the movement of the beam in the direction of the gate.

5. In an automatic gate lifting latch, the combination of a gate movable in a guideway, having a hookextending upwardly at the upper edge of the gate, a lifting beam therefor comprisin spaced supporting members, a latch comprising a pair of plates connected by a pin at one end for engaging the said hook, a pivot extending through the supporting members upon which the latch plates are mounted, the'edges of the latch plates at opposite sides of the pivot having shoulders thereon, a weighted arm mounted upon the pivot having a bar to engage the shoulders for moving the latch in a direction to engage in the hook of the gate or to rotate the latch free from engagement with the hook, depending'upon the shoulder engaged by the weighted arm.

-6.A structure in accordance with claim 5 in which the lifting beam comprises two members spaced apart and the pivot upon which the latch is'mounted has a head at one end and-extends through the members with a notched projection at the other end, and a latch attached to the outside of the member adjacent said other end and engaging the notch of the pin for holding it releasably in place.

7. A structure in accordance with claim 5 in which the weighted arm has a handle means projecting therefrom for manually moving the arm from its engagement from one shoulder of the latch plates to the other.

8. A structure in accordance with claim 5 in which the supporting members comprise a pair of channels spaced apart, a pair of plates fixed to the channels and extending upwardly therefrom with a supporting pin connecting the upper ends of the fixed plates at a distance above the beam for engagement of a supporting hook therewith, and the weighted arm being rotatable upon the pivot directly between the fixed plates and be tween the supporting members and the said latch plates from a position engaging one of the shoulders of the latch plates to a position engaging the other shoulder free from contact with the supporting hook.

LEROY F. HARZA. 

